Frustrating BB Problem

This is damned frustrating...

I'm rebuilding my 'cross bike with Campy Centaur components. I've stripped everything, but I can't seem to get the bottom bracket to budge. It's a Shimano UN52, and when I tried to loosen the drive side BB cup [English thread, loosen clockwise], it just doesn't move. How stuck is it? I tried with the torque wrench and I torque a whole lot higher than the 70nM it was supposed to be tightened to. I tried pouring hot water over the BB shell -- nothing... I don't want to force it or break anything, but I'm at wit's end here. This should not be this difficult. In fact, the left cup comes off pretty easily.

Any ideas? I'll even accept ideas that result in the destruction of the BB; I was planning to use it on another bike, but I'd be happy to get another, if necessary.

One more thing... am I right that the cups on the BB-UN52 are plastic?

when walking, just walk. when sitting, just sit. when riding, just ride. above all, don't wobble.

You have loosened the non drive side cup or lockring?? The un52 I have seen are steel or alloy on the drive side. My never fail method.Lock the removal to the cartridge with a QR skewer of a bolt and some washers. Maybe some penetrating oil.Ditch the torque wrench.Long wrench handle or a cheater bar. Sometimes some hammer raps on the wrench handle.

Pokey... Good idea! I didn't look, but I presume the spindle is hollow right through. One question, though... how do I anchor the frame, so I can torque out without damaging it? The workstand isn't sturdy enough...

when walking, just walk. when sitting, just sit. when riding, just ride. above all, don't wobble.

You'll need to apply more force. Clockwise to remove is correct for the right side.

My preferred tool for this is a long flex-handle Craftsman 1/2 ratchet. The great thing about the flex handle is that you can set it so that your hand is pulling in the same plane as the ring, so the tool doesn't tend to cant sideways.

UN52 rings are plastic on the left side only. The right side is steel, and is part of the housing of the BB.

I can see that this is not an unusual problem. My main fear is that I will damage the frame or the threads [if I do, I'm buying an Empella]. There's a wrench shop around the corner from me, and I'll see if the wrench can help me out with this.

when walking, just walk. when sitting, just sit. when riding, just ride. above all, don't wobble.

Originally posted by Sheldon Brown You'll need to apply more force. Clockwise to remove is correct for the right side.

My preferred tool for this is a long flex-handle Craftsman 1/2 ratchet. The great thing about the flex handle is that you can set it so that your hand is pulling in the same plane as the ring, so the tool doesn't tend to cant sideways.

UN52 rings are plastic on the left side only. The right side is steel, and is part of the housing of the BB.

Good luck!

Sheldon

Wow, is this for real? If it is, I want to say hi and welcome Sheldon! I've gleaned tons from your site. Your presence here would be huge, equivelant to having Armstrong start posting in the race forum IMHO.

I can see that this is not an unusual problem. My main fear is that I will damage the frame or the threads [if I do, I'm buying an Empella]. There's a wrench shop around the corner from me, and I'll see if the wrench can help me out with this.

If you clamp the frame itself in a repair stand and apply heavy leverage to the BB, it could conceivably dent a frame tube if there's nothing inside (meaning, the seatpost doesn't go that far into the frame).

If you get a big breaker bar or ratchet for leverage, one possibility is simply to lean the bike against a wall with the wheels on, position the breaker bar at the 3 o'clock position, and push down. This puts the stress where the bike's made to take it. Alternate idea: loosen the repair stand's clamp-rotation lock so you can rotate the bike and clamp in the stand without too much effort (as a "safety valve") and then use the frame and wrench as opposing levers, rather than relying on the stand to counteract your effort. Not likely you'll dent the frame with your bare hands

Unless your frame has unusually delicate threads, it's not likely you'd damage them unless you cross-threaded the BB and forced it in.

If you hold the BB tool onto the cartridge using a bolt and washer, that works great, but the bolt does prevent using a ratchet or breaker bar. In this case you would want to pick up a wrench that fits the flats on the outside of the BB tool, or perhaps clamp it in a bench vise and use the frame for leverage.

put the BB extractor thingy in a vice.. then put the bike on top of it and turn the bike.. u can get a million times more torque by using the bike to loosen it than a wrench. i do that with freehubs and cassettes as well. easier to turn the whole wheel then a wrench

Velosophy#1: It is better to have a bicycle and no money , than money and no bicycle ! Velosophy # 2 : "Winning is simple, but not easy." #3: "Give a man a fish and he shall eat for a day , teach him how to fish and he will sit in a boat and drink beer all day"

I got the BB out by putting the tool in a vise and turining the bike. It had been assembled -- by Kona -- without anti-sieze or grease on the threads. Since then, I have replaced the BB again, this time with one with a longer spindle to accomodate the oversized, wide-spaced chainstays. Rides like a dream... a muddy dream...

when walking, just walk. when sitting, just sit. when riding, just ride. above all, don't wobble.